In providing perimeter security, one can currently choose from many systems available in the world marketplace. One such system includes non-lethal electric fencing (NLEF). NLEF systems provide significant deterrence value and provide low incidences of false or nuisance alarms; however, they generally provide less detection value than other systems. NLEF systems function by monitoring change in fence voltage, for example, a sharp decrease in voltage that may occur if someone were to touch a fence wire while standing on the ground. However, if someone were insulated from the voltage, there generally would be no corresponding decrease in voltage, and thus, no detection that an intruder or escapee were penetrating the barrier. For example, if an intruder or escapee were to electrically isolate himself from the NLEF by using a plastic container or electrically insulated clothing, he would be able to spread or climb fence wires without detection.
Another system includes taut wire fencing. While taut wire systems provide low incidences of false or nuisance alarms and very good detection value of an intruder or escapee attempting to spread or climb a wire, they generally fail to provide much deterrence value as most are not electrified. Also, taut wire systems are generally among the most expensive perimeter security systems available because of the use of complex strain gauges, sophisticated electronics, or sensitive transducers to measure and detect tension changes in the wire array. In addition, complex algorithms are generally required to maintain tension on each wire because environmental factors cause wires to gradually expand and contract, causing tension on individual wires to vary over time. According to one industry expert, a taut wire sensor post can cost as much as $29,000 and a taut wire system can cost $150-$170 per foot to install.
Other systems may use special “profile” posts that create a path to ground if fence wires are spread. As such, if the wires are spread far enough apart, they come in contact with these special posts, cause a short-circuit, and in turn, an alarm will sound. The problem with these specialized, grounded posts is that they require the use of the wire array to be part of the detection system for wire spreading. As a result, they are often easily defeatable. The point of contact between the high voltage electric fence wire and the special post is exposed and can easily be insulated or tampered with by an intruder/escapee. These systems also require that electricity be flowing in the fence wire array, which is not desired by some users.
It should be appreciated that a large number of other fencing systems exist in addition to those described above; however, these descriptions are provided to demonstrate that there are advantages and disadvantages with using any system. As such, in an attempt to address certain shortcomings of these systems as well as others, the system of the invention is provided.